Embodiments of the present invention relate generally to disk drive systems and to lubrication of recording media within the systems.
Hard disk drive systems typically include one or more rotatable disks having concentric data tracks defined for storing data, a recording head or transducer for reading data from and writing data to the various data tracks on each disk, and an air bearing slider for precisely holding the transducer element in close proximity to a selected track. Lubricants have been placed on the disk surfaces in order to prevent undesirable interactions between the head and the disk.
The head and disk interface in a disk drive can be continuously lubricated by use of a vapor phase lubricant reservoir system. U.S. Pat. No. 4,626,941 describes a system in which a bulk lubricant source is kept at a warmer temperate than the heads and disks. However, this approach led to problems related to the need to prevent excessive bulk-phase lubricant from condensing onto the head and disk surfaces. Other approaches are described in U.S. Pat. No. 4,789,913 to Gregory et al., U.S. Pat. No. 5,229,899 to Brown et al., and U.S. Pat. No. 5,331,487 to Gregory et al., which are each hereby incorporated by reference in their entirety.
Embodiments include a method for forming a lubricating perfluoropolyether (PFPE) film on one or more disks in a disk drive system, including providing a first component of PFPE molecules having an aggregate vapor pressure in the range of 1xc3x9710xe2x88x926 to 1xc3x9710xe2x88x9211 atm and a second component of PFPE molecules comprising at least 5% of the total number of molecules of the first component, wherein the second component includes an aggregate vapor pressure lower than that of the first component. The method also includes mixing the first and second components to obtain a homogeneous composition.
Embodiments also include a method for lubricating a rotating disk in a disk drive within an enclosure, comprising positioning a reservoir within the enclosure and spaced a distance from the rotating disk, and filling the reservoir with a single phase liquid comprising a first component of PFPE molecules having an aggregate vapor pressure in the range of 1xc3x9710xe2x88x926 to 1xc3x9710xe2x88x9211 atm and a second component of PFPE molecules comprising at least 5% of the total number of molecules of the first component, wherein the second component includes an aggregate vapor pressure lower than that of the first component.
Embodiments also include a disk drive system including at least one disk adapted to store data, at least one transducer adapted to read and write data to and from the disk, and a lubricant composition disposed in a reservoir spaced a distance from the disk, the lubricant composition includes a single phase liquid comprising a first plurality of molecules having a first vapor pressure and a second plurality of molecules having a second vapor pressure that is less than the first vapor pressure.
Embodiments also include a lubricant system for use in a disk drive system, including a homogeneous mixture including a first group of perfluoropolyether molecules having a first mean molecular weight and a second group of perfluoropolyether molecules having a second mean molecular weight, wherein the first mean molecular weight is less than the second mean molecular weight.